The witness was given 'blanket' protection from prosecution. [=the witness would not be prosecuted for anything]
The job was her 'security blanket'. [=the job was the thing that made her feel safe and secure]
A 'blanket' of gloom spread over the crowd when they realized their team would lose.
(..) up to some serious shit. What I want from you is his Saudi e-mail Ammar, bro, I know that you know this dude. Just give me his e-mail, and I will-I will give you a blanket. I will give you a blanket and some solid food. I know that you know him. I told you before, I won't talk to you. (..)2012 Zero Dark Thirty